Semi-automatic telephone system.



M. SCHWARTZ.

SEMI-AUTOMATIC TELEPHONE SYSTEM. I APPLICATION FILED NOV. H), 1913.RENEWED JUNE 15, 1918.

Patented Jan. 28, 1919.

2 SHEETS-SHEET I.

m. SCHWARTZ. SEW-AUTOMATIC TELEPHONE SYSTEM. APPLICATION FILED NOV. [0.1913. RENEWED JUNE 15. I918.

- '1,%92,522\ Patented Jan. 28, 1919.

2 SHEETS-SHEET 2.

' particularly :to a private branch exchange systemthat is, a system inwhich small UNITED STATES PATENT OFFICE.

MICHAEL scnwnnrz, or LOS niveanns, CALIFORNIA, AssIGnoR T0 Aurel/linersELEc'rnIc COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

SEMI-AUTOMATIC TELEPHONE SYSTEM.

- Specification of Letters Patent.

Application filed November 10, 1918, Serial No. 800,163. Renewed June15, 1918. Serial No. 240,251

T 0 all whom it may concern Be it known that I, MICHAEL SoHwAR'rz, acitizen of the United States of America, and

resident of Los Angeles, Los Angeles' following is a specification.

My invention relates to improvements in semi-.alutomatm telephonesystems, and more manual private branch exchanges are employed inconnection with automatic or semiautomatic systems.

Ordinarily in such systems therelease of the connection irommoaning-subscriber of a private branch exchange'togthe main exchange iscontrolled by the'operator at the private branch exchange. Since insmaller exchanges the operator generally has other I duties to performthan attend to the switchboard, she does not always promptly respond tothe disconnect signals, and consequently the line of the calledsubscriber may be tied up for a considerable time after the subscribershave signaled fora disconnection.

Connector switches which maybe released by the called subscriber haveheretoforebeen devised, but they are open to certain objections.Accordingly the object of my invention is to provide means whereby theordinary form of connector switch which is released by the callingsubscribe-r can be employed in these privatebranch exchange systems, andwhenso' usednre released by the called subscriber hanging-up hisreceiver that is, when these connector switches are employed forestablishing a connection between two lines, in which connection noprivate branch exchange is involved, then the connector is released-inthe ordinary way by the calling subscriber hanging up his receiver.When, however, a call is made through a. private branch exchange, thenit is not necessary to-wait for the exchange operator to release theconnection, but the connection is released immediately upon the calledsubscriber hanging up his receiver.

My invention will be more clearly understood by reference to theaccompanying drawings, vcntion in connection with a semi autoin which Ihave illustrated my inmatic telephone system of a particular type. Ihave there indicated a private branch ex change consisting of a cordcircuit of a wellknown type, with a trunk line extending to a mainautomatic exchange, in which automatic exchange I have indicated anautomatic connector switch in which the trunk line terminates. Thisconnector switch is adapted to make connection directly with the calledsu'bscribers line. As-orclinarily constructed, this connector switch hasaccess to but one hundred subscribers, and it will, of course, beunderstood :that where larger exchanges are employed the ordinary methodof inter osing first and second selectors between e connector witch andthe trunk line extending to the private branch exchange will beemployed. The manner in which these switches are interposed in the trunkline and their operation are well understood in the art, and as theyform no part of my present invention, it is not thought necessary toillustrate the same.

Figures 1 and 2 represent a complete connection between a calling manualtelephone M and a called automatic telephone A in said system.

The telephone M (Fig. l) is an ordinary manual telephone'comprising areceiver 2, transmitter 3, switch-hook 4, ringer 5 and condenser 63. Atthe central office the line of thetelephone M is equipped with the usualline relay 7, line lamp 8, cut-ofi' re- Patented Jan. 28, 1am.

with the automatic exchange extends from the jack J (Fig. l) to theconnector H (Fig. 2). The drop14 is normally bridged across the trunkatthe jack'J for use when a call is extended from the main to the branchexchange. board the trunk is also provided with a slow acting neutralrelay loand a polarized lJ ll At the manual switch-- An :mtemeticeniQ-"mdi11g (1e else provided, thm git. the meu'ch the operator maycontrol switches at the automatic exchange in erder 1'0 eistuoiieh thedesired cmmectim.

This; calling device may be of any desired type sue/11,, for examplethat shown in. British patent to S. k}, S. Dicker N0. 29,-- (551 of1910, and is herein represented elmply by pair of impulse springs 17.

The switch C (Fig. 2) is of the general. 'ype of subscribexs individualswitch shown in British patent to R. WV. James N 26. 301 ef 1,906, moreeleeely resembling, how ever the particular type shown in British mtent$0 T- (at. Martin Nu L419 075 1910. his'switch is controlled in theusual H1211!- ner by a master switeh (not shown} which would, be similarto the master switch 1) which eentrols the line switch (1 of the u; Hadline, Whih line switch is eimilar to the swiitclg-l Ck Y The mmtieetor H(Fig fl) isnf the gem e1": eonnectexr switch diselos (Yin Lettee PatentNe. 815,1?6 r441 13,- 1906, to Keith, Erieksen teen, the circuitshoweve'n eeing e'lodiit'ied in a. nmzmer similar t0 that sshOWn tn staidBritish patent to T G. Martin No. L419 0t 1910, 50 as to adapt theswitch 11 amezfetien. in a system in which the cent .1 attic-e :qppantns controlled by imflelivered oven: the two sides of the The connectoris providei shaft (not shown) marrying the -14; and 45 and is contra'SQC by i erient magnet: 46 and the rotary meg- -17. Th2 usual] sideewteh cemgnisifig 4?, -19, and 51 is emztmiled t0 nmgnet 52 in 31weflitmmm The-magnet the usual we Benet. (Che tine why is'eened with theiine thruugh the revere} A wings 0t :1 Lwt eilii'fl! heck-bridge relay'mzgzh the vindir s of which the (M ti t GHQ is; proviecu with BathingCHITHEEQJ.

U We 5G and ii? are slow :mtin Aft B there ehewn :1 ringw Qenee ringingfor k he 021N041 s11. ihm: it Q there'e she. {a busy sigmzi: 5;; veerentcenipmsmgzj en indm'hon mi 58 Mar ime w nter J nutenmtiv tr I is;fiimihw t0 mmmi teephene In! (Fig. 1) with the z xi 0 veltsemtingg (1et; me)? be the line. after Wlzieh one pm 4 preferably ene A generaflee/rip tmving been ;g. u, it H. new (zoln'xeetm'a may he, manualtelephone M. :1 A phone A, and 110W said released by the hanging at thecalled telephene.

71m. SWitfihjllg eppe :utus lifieios 7 general Welt knewn in the emscribed in the 'ymblimfiene 1511 e t0 its ope-Mien Wm exp 01 lessgenerr-fl mamsmz t, pen, t of the receiver fi'em 'ii'xe switch 1 s11bstat ion M prep-ms! the talking 001162.15: the line why I circuit ofthe A1116 emit-0r. The 01 the plug P key K to fine and med.

m stem the.

ends by in gmmm then 121111;; t0 batten .L energizmg, discormeets the YJ I step? is previded Wit? t:e "m;g "'N'Iiflltfl (We-1; r emit extend: twinding: of the thence we): the h UUC'HHE". the subr'.

4 0 her suite of i and the seeend coil to the lun'egrrvwue B. The relay1 a shunt meme z'ee 'mnee (33. [been vt infra itmm 52:

After lean-n1 ping into Hi we eelmm'ieu dim-01111001". me hm v" a; thesame time the tt'erci-(i into n e t. thetyunk commet rate? 1W Uponproper direction to maintain the contact of springs 76 and 77 closed.while the relay 15 is short-circuited by the circuit passing through thesprings 76 and 77. The r lay winding 81 (Fig. 2), upon energizing,attracts the armature-21 to close the circuit of the operating winding89, which attracts the. plunger arm 18 to extend the connection throughthe bank springs to the connector H and the cut-oil armature 20 todisconnect the line relay from the line. Before the armalture 21 dropsback to open the circuit of the operating winding 89 after the linewinding 84 is disconnected from the line, the holding winding 86 isenergized in the following manner to hold the switch in its operatedposition. When the connection is extended to the connector H through thesprings 22 and 26 and and :29 by the operation of the switch the linerelay 51 is energized by reason of the closed bridge across the trunkthrough the relay 16 (Fig. 1). The relay 54:. upon energizing, closesthe circuit of the relay 56, which, by forcing the springs 88 intocontact. completes a circuit extending from ground G through saidsprings and through the line switch after the winding 89 isdeenergize'd.

bank springs 27 and 2.3 and the winding 86 to the battery B. Theenergization of this winding serves to hold the plunger arm and cutoffarmature in their operated positions guarding potential is also extendedfrom ground G at the connectorthrough the springs 88, 27 and 23 and overthe conductor 90.to the connector private bank contacts 30 in the bankof each connector which has access to the trunk line. Upon the closureoi the springs 2-1 and 28 of the switch C", the master switch operatesin a wellknown manner to move the pluiigers of the idle switches of thegroup to a position opposite the terminal of an idle trunk line. The

-' operator now operates the key K (Fig. 1)

to open the bridge across the-trunkthrough the relay 16 and substitutetherefor'a bridge through the springs 17 01" .b en calling dev1ce.

She now operates said calling device for the respective digits of thenumber of the called substation, which will be assumed to be 20. Uponthe operation of the calling device for the first digit 2. the impulsesprings 17 (Fig 1) are separated twice momentarily. each time breakingthe circuit of the line rclav 51 of the connector H. Therelay 56 of theconnector being slow acting does not dci nergize during the momentaryinterruptions of its circuit by the relay 54. and consequently each timethe said line relay dcenergizcs in response to said impulses. an impulseis transmitted over the circuit ex tending from gronudii" through thespring 112 and its hack conta t. spring l13 iand its front Contact.relav -7. vertical nuigncr 4:6 and the side sw tch wiper 31 to the bat-'tery lead 85. The magnet 46 operates in response to the two impulsesreceived'over this circuit to raise the switch shaft two steps, whilethe slow acting relay 5'? is energized to close the circuit of theprivate magnet and to maintain it closed continuously until after the laimpulse for the digit is transmitted. After the last impulse istransmitted, the relay 5? deenergizes and opens the circuit of theprivate magnet 52, which, upon deenergizing. permits the side switch topass from first to second position in a well-known manner. The movementof the side switch wiper 51 from first to second position transfers thebattery connection from the vertical magnet 46 to the rotary magnet 47.The operator now operates the calling device for the last digit 0,whereby a series of ten impulses is transmitted through the rotarymagnet 4:7 in series with the relay 57, whereby the shaft wipers arerotated onto the contacts of the desired line. The relay 57 operates inresponse to the impulses for this digit to again close the circuit ofthe private magnet 52. W'hen the relay 57 deenergizes after the lastimpulse for the last digit is transmitted. the private magnet 52denergizes also, if the called line is idle, and per mits the sideswitch to advance from second to third position, whereby. through themedium of the side switch wipers 1-8 and 49. the connection is completedthrough the shaft wipers 43 and 44 to the called line. The side i switchwiper 50, upon passing to third position, provides a guarding potentialfor the connector private bank contacts of the called line and energizesthe cut-off windingll-t of the switch C to disconnect said switch fromthe line and close the contact 115 in the talking circuit. The sideswitch wiper 51 of the connector, upon passing to third position. closesthe circuit of the ringing relay 116 through the interrupter 117. The

relay 116 thereupon begins to operate to in- A the tall by removing hisreceiver. the called substation is provided with talking current overthe circuit extending from ground G at the connector through theback-bridge relay 5:"). contact of Splllllls 118 of the privatc magnet52. thence over the heavy conductors to and through the substatioi-i Aand back over the otlu-r side of the line,

. I s to again com ch01;

anti? aft reaches its estm' amnion m :5 switch mu the relax.

cmmu I u (11: r

zmreiease md its brusk com act 1 is inim'rzmted at Th1 var, when gne"Quitv nit hen. the S11 raw;

tt'ery lead.

izing, (-4 i112 com'icctor switch to its; normal p0- fxs awn sir nowe,I}

ed cont (m spm ng 113 'na'ft-con'troll 1). e cross the tr G thr unmet,

13 to the b i act posihnn 11 0mm? wmchn m- .pmn't 1; fin: and

This

9 will cause the line d a a-ngement for 1 If the J before us reumvsr,

the same ned by the Idem that 110 111 nnmtm; 1)

same manner 'Was'; ()blll'ififfid *mth. the ,5

leciim H, passing cwer hers de- .aViSG mags up hlixp 10, Wilma the plugsP ackx m gize and rees 111 s ope 1:; systmn. may sysfiu (1 mm" may than120 trunk and any the operator :1 9b

"xchangaa to the used as well for :11 SWlilfihhOflld nt drop 14: (Fi'li'n'nngh 121m '0, "iahe'opwrz subs hm? deiinergjlzes and 1'0- givewhen (1 f1 15 rm'wsved from he ed subscrliimr wanking of the i the(30111 CA to ,the

sari

the

mpon m the 3 idge across the trunk 0 d (3 tm to define! :wiltch unk edbefore, the trunk .2113

a the n' :16 \he aut- (f mid the L in thc b QUITE L around hangs up maytum m) and k n 111a 'X m ing (1 mam] seen that I have (k M 0 ml, m0;

non Hmh.

5. been man 13., calls 1" [I opp hushe the 211 1 oumt p ch in .1

nutonmti s (161141 Jew mmmc:

Q I l 15 trol of the calledsubscriber, which control is independent ofany action on the part of the operator at the private branch exchange.Thus it will be seen that the connection will be released either by theoperator taking down the connection, or, 'if she should neg- While Ihaveillustrated and described my invention. in connection with automaticapparatus of a particular type, it will, of course, be understood thatmy invention is not limited to such use, but that it is adapted for usein connection with other forms of automatic apparatus.

What I claim as my invention is 1. In a telephone system, a plurality'otsubscribers lines.,an automatic switch for establishing connection withone of said lines. a trunk for extending a connection to said switch,inductive means separating the calling side of th trunk from the calledline. and means in the calling side of said trunk controlled by thecalled subscriber-for releasing said switch. y

2. In a telephone system, ,Zt- 1)l1l1'2Illt of subscribers lines. anautomatic switch "for, establishing connection with one of sa d lines.means including a trunk for extending a connection to said switch,inductive means separating the calling side of the trunk from the calledline. a bridge across the calling side of-said trunk. and meanscontrolled by the called subscriber for controlling said bridge torelease said switch.

3. In a telephone system, a plurality of subscribers lines. an automaticswitch for establishing connection with one of said lines, meansincluding a trunk for extending a connection to said switch, inductivemeans separating the calling side of the trunk from the called line. abridge across the calling side of said'trunk, and means controlledbythccalled subs riber hanging up his reccivcr for controlling saidbridge to release said switch.

4. In a telephone system, a plurality of subscribcrs lines, an automaticswitch for establishing connection with one of said lines, meansincluding a trunk for extending a connection to said switch, meanscontrolled by the called subscriber for reversing the current in saidtrunk, and meansin said trunk responsive to said reversal of current forcontrolling the release of said switch.

In atclephone system, a plurality of subscribers lines, a, connectorswitch for esrablishing connection with one of said lines, meansincluding a trunk line for extending a connection to said'switch.inductive means separating the calling side of the trunk from the calledline, a bridge across the calling side of said trunk, means controlledby the caliedsu bscriber for opening said bridge, and means controlledby the opening of said bridge to release said switch.

(3. In a telephone system, a plurality of subscribers lines. a connectorswitch for establishing connection with one of said lines, meansincluding a trunk line for extending a connection to said switch, abridge across said trunk, means controlled by the called subscriber forreversing the flow of current in said trunk, means controlled by saidreversal of current for opening said bridge, and means controlled by theopening oi said bridge to release said switch.

7. In a telephone system, a plurality of subscribers lines, a connectorswitch for cstablishing connection with one of said lines, meansincluding a trunk line for extending a connection to said switch, abridge across said trunk, a baclcbriclge relay in said connector, meanscontrolled by the called su'bscriber hanging. up his receiver fordeenergi zing said baclcbridge relay, means controlled by thedeenergization of said relay for opening said bridge, and means controlled by the opening of said bridge to release said switch.

S. In a telephone system, a plurality of gizing said back-bridge relay,means con-.

trolled by the deenergization of said relay for reversing the current insaid trunk, means controlled by said reversal of current for openingsaid bridge, and means controlled by the opening of said bridge torelease said switch. v

9. In a telephone system, a plurality of subscribers lines, an automaticconnector switch for establishing connection with one of said lines,means including a trunk line for extending a connection to said switch.inductive means separating the calling side of the trunk from the calledline; a bridge across the calling side of said trunk, means controlledby the called subscriber for temporarily opcn-ing'said bridge, and meanscontrolled by the opening ofsaid bridge to release said switch.

10. In a telephone system, a plurality of subscribers lines, anautomatic connector switch for establishing connection with one of saidlines, means including a trunk line for extending a connection to saidswitch, a bridge-across said trunk, means controlled by the calledsubscriber 'for reversing the polurizou relay acting relay lgo, moans vopen said 1 1y the opening in ality 11a plied 1119s, an

1 inolud 4 r x connection Y means in said tion of said to a called e of321 id. Hunk con snlisomlior for releashone. system, a plurality ofoir'ouit adapted to one 01 mid limos, an autosivitoli, merino includinga oni'onding a cm'mestion from (i swim- 1, means in said trunk i rationof said switch to a, ()fillfid lino, z calling side Eiil. line, abridgeid trunk, and subscriber for Laseamid switch, plurality of circuitadapted to oi said Ii 19-5, on ontomoons il'iclnding a; g o,COI'IMQCiLlOH from ;'.,.h, moan. n mid trunk .1 operation of said switchconnection. .10 :1 called line, o muollmii by the called subscriber for(jiiilfil'ii said trunk, and

" .z-yosponsivo to said refor controlling the release am, a. pluralityof oiro'uis adapted 0 of said lines, an 2 -1to- 1;: l'noans including a,tomiiug' connection from v21s 11 said trunk n of vmid switch to a,sailed line, the calling sizle line, a, byido'e if ii we for. con- 1113;83nd bridge, oml moanswnti'oilocl lw tho @Pfinlllg 01 said bridge torelease ml. m'i'itflll,

imam; controlled by a; i

for opening said bridge, and means mmso trolled by the opening of midbridge for releasing said switch.

17, In a telepholo system, a almwaiity of subscribers limos, u z-ox'rl(rim-nit adapted to he mnnovtecl with ono of, said limo, an 85 automaticoonnevtor switch, means inolucling a trunk line for extending aconnection from id cord to said S\\'ll-1ll, means in said trunk. forcontrolling the ope m'aion said swim-i1 110 vompleto a. connection tocalled 9'0 line, inductive means si apornting tho calling side of thetrunk from the called line, a bridge across the. nailing side of saidtrunk, moans controlled by the olled sulmcriloer for temporarily openingsaid. bridge, and means coi'itrollod by the opening of said bridge torelease said SWit-(lL 18. In a telephono system, a plurality ofsubscribers lines, a cord circuit adapted to be. connected with onoofsaid linoo, an :iutrr mantis connector switch, means including a trunkline for extending a (-onnectvion from said cord to said switch, meansin said trunk. for :ontrolling the operation of mid oil to complete acormovtion to :1 mliml. line, means controlled by the called subsx.ilror for reversing the current in said trunk, means 1.9 In a tqlophonesystem, a pin 'alit y of subsc' l ms 1m. autonmtm switch for ostdl'iiisiiing connection with one of said lines, a trunk, 11 nonq'mmericalautomatic switch for connecting said trunk with amid first switch, andmeans in said trunk vootrollod by the called subscriber forrco10'a.-;ing said first switch.

20. In, a fielephone system, a plurality of" 1212 subscribers lines, anaufon'mvtic Switch for establishing connection with mm of said lines, atrunk, a non-numerical. aufolnatio switch, means including said trunkand switch for extending connection to said first 12'? switch, a bridgeacross Enid trunk, and means controlled by the, called subscriber forcontrolling said bridge to relenso said firstswitch,

22. In a telephone system, a plurality of subscribers lines, anautomatic switch for establishing connection with one of said lines, atrunk, a non-numerical automatic switch, means including id trunk andswitch for extending count; on to said first switch, means controlled bythe, called subscriber for reversing the eurrent in said trunk. andmeans in said trunk responsive to said reversal of currcn't. forcontrolling the release of said first switch.

23. In a telephone system; a plurality of subscribers lines, a connectorswitch for establishing connection with one of said lines, a trunk, anon-numerical automatic switch, means including said trunk and switchfor extending connectionto said first switch, abridge across'said trunk.means controlled by the called subscriber for opening said bridge, andmeans controlled by the opening of said bridge to release said firstswitch. 1

24. In a telephone system, a plurality of subscribers establishingconnection with one of said lines. a trunk,-a non-numerical automaticswitch, means including said trunk and switch for extending connectionto said first switch, a bridge across said trunk, means controlled bythe called subscriber for reversing the flow of current in said trunk.means controlled by; said reversal of currentfor opening said b idge.and meaiis con trolled by the opening of said bridge to release saidfirst switch.

25. In a telephone system, a plurality of subscribers lines, a connectorswitch for establishing connection with one of said lines, a trunk, anon-numerical automatic switch, 7 means including said trunk and switchfor extending connection to said first switch. a bridge across saidtrunk. a. backbridge relay in said connector,'means controlled by thecalled subscriber hanging up his receiver for energizing saidback-bridge relay, means controlled by the cnergizaion of said relay foropening said bridge. and means controlled by the opening of said bridgeto release said first switch.

26. In a telephone. system, a plurality of subscribers lines, aconnector switch for establishing connection with one of said lines. atrunk, a non-numerical automatic switch. means including said trunk andswitch for extending connection to said first switch, a

bridge across said trunk, a back-bridgc relines, a connector switch forlay in said connector. means controlled by the called subscriber hangingup his receiver for energizing said back-bridge relay, means controlledby the energization of said relay for reversing the current in saidtrunk, means controlled by said reversal of current for opening saidbridge. and. means controlled by the opening of said bridge to re leasesaid first switch.

27. In a telephone system. a'plurality of subscribers lines, anautomatic connector switch for establishing connection with one of saidlines. atrunk, a non-numerical automatic switch. means including saidtrunk and switch for extending connection .to said first switch, abridge across said trunk. means controlled by the called subscriber tortemporarily opening said brie and means controlled by the opening ofsaid bridge to release said first switch. 8

28. In a telephone system. a plurality of subscribers lines, anautomatic connector switch for establishing connection with one of saidlines. a trunk, a non-numerical automatic switch, means including saidtrunk 9 and switch for extending connection to said first switch. abridge across said trunk. means controlled by the called subscriberfor(cm-- porarily opening said bridge, means con- I trolled by the calledsubscriber forreversing the current in said trunk, means controlled bysaid reversal of current for temporarily opening said bridge. and meanscontrolled by the opening of said bridge. for releasing said firstswitch.

29. In a telephone system, a pluralityof subscribers lines, meansincluding a connector switch for establishing connection with one ofsaid lines. a trunk. anon-numerical automatic. switch, means includingsaid trunk and switch for extending connect-i611 to said first switch. abridge including a piolarizcd relay across said trunk, a. slow actingrelay adapted to be included-in said bridge. means controlled-by thecalled subsllv scribcr for controlling said relays to monien' tarilyopen said bridge. and means controlled by the opening of said bridge torelease said first switch.

30. In a. telephone system. a plurality of subscribers lines. a cordcircuit adapted to be connected with one oi said lines. an automaticconnector switch. a trunk line, a nonnumerical switch, means includingsaid trunk line and non-numerical switch for eX- 129 tending connectionfrom said cord to said first switch. means in said trunk for controllingthe opcration of said switch to complete a connection to a called line,and means in said trunk controlled by the called subscriber forreleasing said first. switch.

31. in a telephone system, a plurality of subscribers lines. a cordcircuit adapted to be connected with one of said lines. an automaticconnector switch, a trunk line, a non- 30 subscrilw fines, o cord dd: Lbe conncc vdo 1 id in; as, on a utm E'INLUC ccnmcctor switch, 2L twink nnnmcl'ic. switch, mcmiac. i fl 1112: {inc and ncnnumerica tendingconnection from said first swimh, means in said is; for m tloi iin'g theopcmtim'l of said sswnch to con.-.-- plate a connection to :1 calledHue, n'muns con."- troElcd by the coiled subscriber for reversing thecurrent inoaid trunk, n; d me: Q, in said trunk responsi'vc to said rc*crszd of (311?! n; for control iing the rei'ca e. of said first:switch.

33. In a tc iephone a morality of subscribers lines, a cord circuitndaph-zd to be, connected with one of, asdd limos, an cum maticconnector switch m-trmxk line. a; nonnumcricai switch, means iz'icludingsaid trunk line and non-numwiczd swi ch for my tcnding; connection frcmsaid cord to said first switch, mcm'as inscid trunk for confroh ling hcoperation of said switch to compl. a (UIIIIQCHOH to a coiled line, :1bridgeacross snfid trunk. mcanscontrolled by the mfflcd subscriber foropening said bridge. and means controlled by the opening of said bridgeto whose said firsi; switch.

34-. In a telephone sysficm, a pduzudity cf snbsc fibers lines, 1:- cordcircuit, adapted. to be connected with one of said lincsyaxk aut0- maticconnector switch, a trunk line, :1 m numerical switch, means inci'udingsaid trunk fine and non-numerica1 switch for c icndiog conncctionfronmsaid cord to said firstswidch means in. said trunk for controliingthc operation of said switch to completc a connection to :1 calledline, means com troliod by the coiled. subscriber for reversing thc flowof current in said trunk, means c0n-- frol'lcd by said reversal ofcurrent for ope/1' ing -snid 'b'ridge, and means controlled by, theopening of said bridge: for releziming said first switch.

353. In telephone systcs'n, l, plumiity 0;

1 1'01 waging and 11 plumlr'iky 5cm] switch, nacz'ms Including said cmews iuchn'io non-m1 mcmc: switch id cord to cmtion by said m. openingsaid 33 Y 9 opening of mid h d first switch.

phone systcm, a iny; and. mas iliuzi'mf'ing a hunk: lino h hzwifi g"am-tic i and U R'iUfiOYla cont. ,c we!" the two dos of said. trunk incin for connect-- and moans unnoociaitcfi with m Hm (m KAXU In :1 ccalled 7' 1311c mconmmc sa'wiiidmzt; cow 1c two mdcc of mid firms calledHm, 111cc g Enid con-- 'jhom 3y atom twc umlnmgcs, meeting rsxvidcxchcngcm, a I? in ihc first (exmrgrc, ccalled c'imd cwxchangc, noautoirmd witch for mcnns in d" fimt; ox thc cidlcd H11 for re.

4:1. In a icicydmnc systcutl, n'm'miz 11 change, an automatic cziclumgca trunk E cou'nc wing: said QKfhflUgfiS, o mm g c c i thc mannaexchangc, 11 calicd Zinc in the on tomatic exchange, mcnns including mk:1111c and :omaiiic m i-cl MOM):

nm' omdiic Kiwi-n and mc change, an automatic exchange, a trunk lineconnecting said exchanges, a calling line in the manual exchange, acalled line in the automatic exchange, means including a cord circuit,said trunk line and an automatic -switch for connecting said lines, abridge across said trunk line to prevent the release of said switch,means controlled by the operator for opening said bridge, and meanscontrolled by the called subscriber for opening said bridge.

43-. In a telephone system, a manual exchange, an automatic exchange, atrunk line connecting said exchanges, a calling line in the manualexchange, a called line in the automatic exchange, means including acord circuit, said trunk line and an automatic switch for connectingsaid lines, and mechanism associated with said trunk line whereby eitherthe operator at the manual exchange or the called subscriber in theautomatic exchange is enabled to restore the said called line to normalcondition by releasing the connection.

44. In a telephone system, a calling and a called line, means includinga trunk line and an automatic switch having vertical and rotary motioncontrollable over the two sides of said trunk line in series forconnecting said lines, and a relay, associated with said trunk line andcontrollable from the called line for releasingsaid connection.

45. Ina telephone system, a calling and a called line, means including atrunk line and a plurality of automatic switches controllable over thetwo sides of said trunk line in series for connecting said lines, abridge across said trunk line to' prevent said switches fromreleasing,.'and a relay congrollled over the called line for openingsaid 465i In a telephone system, two exchanges, a trunk line connectingsaid exchanges, a

connection.

47. In a telephone system, two exchanges, a trunk line connectlng saidexchangesfa calling line in the first exchange, a called line in thesecond exchange, an automatic switch for completing connections'to thecalled line having vertical and rotary motion, means including saidtrunk line and said switch for connecting said lines, and a relay in thefirst exchange controlled over the connected called line for releasingsaid switch.

48. .In a telephone system, a manual exchange, an automatic exchange, atrunk line connecting said exchanges, a calling line. in the manualexchange, a called line in the automatic exchange, means including saidtrunk line and an automatic switch in the automatic exchange forconnecting said lines, and a relay in the manual exchange controlledover the called line for releasing said switch.

49. In a telephone system, a plurality of subscribers lines, anautomatic switch for establishing connection with one of said lines, atrunk line including a pair of talking conductors for extending aconnection to said switch, indiictive means separating the calling sideof said trunk line from the called line, a bridge across said talkingconductors on the calling side of said trunk line, and means-controlledby the called suliscriber for controllingsaid bridge to release saidswitch.

Signed by me at Chicago, Cook county, Illinois, this 3rd day ofNovember, 1913.

MICHAEL SCHWARTZ. Witnesses HARRY E. Hnnsnnr,

RAY SToxaLY.

